Our Common Future Under Climate Change Climate Change Challenges Ecological Function in the Deep Half of the Planet Lisa A. Levin Center for Marine Biodiversity and Conservation Scripps Institution of Oceanography, UC San Diego, USA July 8, 2015 UPMC, Paris, France CMBC
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Our Common Future Under Climate Change
Climate Change Challenges Ecological Function in the Deep Half of the Planet
Lisa A. Levin
Center for Marine Biodiversity and Conservation Scripps Institution of Oceanography, UC San Diego, USA
July 8, 2015
UPMC, Paris, France
CMBC
50 years ago … This generation has altered the composition of the atmosphere on a global scale through radioactive materials and a steady increase in carbon dioxide from the burning of fossil fuels. - President Lyndon B. Johnson, 1965
50 year later…. This generation has begun to alter the deep ocean…. Via CO2-induced environmental change and resource exploitation
Delving Deeper
• The deep sea – what is at stake?
• Climate Change (T, OA, O2) in deep water
• Consequences for biodiversity & ecosystem function – Past, Present and Future
• A growing human footprint – Clash of climate and exploitation
The largest habitat on earth
• The deep ocean (>200 m) comprises 2/3 of the planet’s surface area and > 90% of its habitable volume
• We have seen < 5% of the deep sea floor thus most marine species are undescribed. • Great depth limits access & measurement capability
•Cold (2-4o C) •Dark (no sunlight) •High Pressure (1 atm/10 m)
•Homogeneous •Stable •Food Limited
THE FIRST 100 YEARS
What Do We Know about the Deep Sea? Why should we care?
New exploration tools reveal a wealth of environmental heterogeneity
SENTRY (AUV)
ABE (AUV)
Photo:D. Stevens
Jason (ROV)
DTIS (photo by D. Stevens)
MULTI BEAM SONAR
HOV
AUV
ACOUSTICS
Seamounts- Underwater Volcanoes 30,000-50,000!
Dense fish aggregations
Crusts rich in cobalt, titanium, nickel, platinum, cerium molybdenum, tellurium,
Lush invertebrate populations
Exceptional Longevity, Slow Growth
Garrardia sp. Leiopathes sp.
2,320 years old
Smooth oreo dory – 100 y Black Oreo-153 y
Sablefish – 114 y
Orange Roughy - 149 y
Sablefish – 114 y
DEEP CANYONS
Photo by P. Tyler
VULNERABLE BIOTIC REEFS
Photo - MAREANO
DEEP CORAL REEFS
Natural Resources Canada
SPONGE REEFS
Pribillof Canyon – M. Ridgeway
Manganese Nodule Fields
• Cover vast areas of the ocean • Nodules grow slowly < 1 cm/million years • Valuable minerals resources (Mn, Ni, Cu, Co)
Cu, Gold, Zn, Silver
Metals News
clccharter.org
en.wikipedia.org
Worlds without sunlight Hydrothermal Vents
Oil, Gas, Gas Hydrates
Methane Seeps Oxygen Minimum Zones
Phosphorites
Courtesy of Rashid Sumalia
The Deep Pelagic Largest migrations, Food for commercial fishes Unknown biodiversity, Genetic resources
Biomaterials – sponge fiber optics - coral bone grafts Anti fouling – for marine or medical
Detoxification – Methyl mercury
Cellulases – fermentation
Pyrolase – used in fracking
Biodiversity as a service
Photograph by Peter Batson
Gulf of Mexico Courtesty of E. Cordes, C. Fisher
Regulating Services: Deep-sea ecosystems are linked to the surface
ocean, the atmosphere and land
The ocean has taken up 28% of CO2 emissions and 93% of heat (since 70s). Photosynthetic production by phytoplankton sinks or is carried to the deep sea (biological pump) 6 month lag Surface pollutants find their way to the deep sea
Heat Uptake Carbon Sequestration Nutrient cycling
$125B/y
Scientific Research Communications Movies, Books, Art Avatar
Artwork by Lily Simonson Artwork by Tanya Young
Rising CO2 emissions
Deoxygenation Lower O2 solubility & Ventilation
OMZ Expansion
Acidification
Warming Ocean
Warming
Atmosphere
Reduced POC Flux
Ice cap melting
Enhanced Stratification
UPWELLING
CO2 + CO32- + H2O ↔ 2HCO3
-
Reduced vertical mixing
Warmer water holds less O2
Projected Change on the Deep-Sea Floor - 2100 (Mora et al. 2013)
T O2
pH POC
What are the biodiversity consequences?
Figure courtesy Ariel Anbar and Timothy Lyons.
Geologic record holds a long history of environmental change and biodiversity consequences
Episodic Anoxia (red) and Extinction Events
BEST PAST ANALOG TO CURRENT CLIMATE CHANGE
ADVENT OF OXYGENATION
PETM CAMBRIAN EXPLOSION
% E
XTI
NC
TIO
N
Sperling et al., 2013, PNAS 110: 13446
Pre-Cambrian Oxygenation and advent of carnivory may help explain the timing and diversity increase
of the Cambrian Explosion (540 MY)
drill holes
nemerteans
chaetognath
The PETM at 55 MY exhibits the deadly trifecta: Rising CO2, and T, declining O2
From Norris et al. 2013
WARMING, ANOXIA, ACIDIFICATION L. Alegret , S. Ortiz , E. Molina , 2009, Palaeo 3
(Alamedilla section -Southern Spain)
55.8 MY: Rapid extinction and recovery of benthic foraminifera across the Paleocene–Eocene Thermal Maximum
No/g % Agglut. %Inf. a H’
Recent Deep-Ocean Warming based on repeat hydrography
Rate of warming below 4000 m
Purkey and Johnson (2010)
Study Finds Earth’s Ocean Abyss Has Not Warmed
> 2000
Llovel et al. Nature Climate Change 2015
Deep Argo
Nature Climate Change 2015
Warming to > 1.4oC has allowed a
Lithodid crab invasion in the Palmer Deep,
Antarctica
< 850 m No crabs
> 950 m With crabs
BIODIVERSITY CONSEQUENCES
Smith et al. Proc. R. Soc. B 2011
Neolithodes yaldwyni
Warming may dissociate gas hydrates, pervasive throughout the margins and expand seep ecosystems
www.soundwaves.usgs.gov
pH Changes North Pacific Total pH Change (1991-2006) Atmospheric CO2 + respiration
North Atlantic Deepwater formation draws down high- CO2 water with transport by boundary currents.
17-21% of N. Atlantic seafloor > 500 m will experience a 0.2 unit drop in pH by 2100.
Byrne et al. 2010
Gehlen et al. 2015
Norwegian corals
Norwegian Corals
Differences in aragonite saturation between ocean basins affect deep-water calcifiers.
Paicifc OMZ corals
Ωarag = [Ca2+][CO3
2-]/Ksp
Temperature rise and saturation state decline will induce loss of habitat suitability for Australian deep-sea corals
Omegaarag > 0.9 and T 7° C
Solenosmilia variabilis projection for 2100
Thresher et al. 2015 Nature Climate Change
Hypoxia is widespread in the oceans at upper bathyal depths
200 m
800 m
Oxygen minimum zones (OMZs)
Blood Pigments (Hemoglobin) Enhanced Surface Area
OMZ’s are not Dead Zones! Adaptations Abound
Small body size long/thin shape
Functional Consequences of Low O2 in OMZs
Altered Carbon Processing
Altered Size Structure and Composition
Rapid Diversity Shifts
Woulds et al. 2007, Levin et al. 2009, Gooday et al. 2009, Levin et al. 2013
Pakistan margin
Foraminifera Macrofauna Megafauna Nekton
Reduced Bioturbation
Reduced Colonization
700m 737m 800m 850m
900m 940m 1050m 1100m
14 of 28
stations (50%)
have zero
predators
ANOVA: F3, 64 = 20.4
p < 0.0001
Sperling et al., 2013, PNAS 110: 13446
Very low oxygen is associated with loss of carnivores in OMZ sediments (Polychaeta)
ANOVA: F3, 64 = 14.25
p < 0.0001
OMZ
(200-300 m)
Above/Below OMZ
(100, 500, 800 m)
Chemosynthesis is common among metazoans within the OMZ
Light C and N signatures reflect influence of chemosynthesis.
North Chile Margin (Iquique)
Thyasirids
Lucinoma aequizonata
Acharax
Olavius crassitunicatus
Siboglinids
TAXA WITH CHEMOAUTOTROPHIC SYMBIONTS
Oxygen decline in the tropical O2 minima
Stramma et al. 2010
O2 in 1964-70 vs 1990-2008 from 200-700 m in tropics, subtropics At 200 m the area with < 70 mM O2 has increased by 4.5 million km2 area
DOSI seeks to integrate science, technology, policy, law and economics to advise on ecosystem-based management of resource use in the deep ocean and strategies to maintain the integrity of deep-ocean ecosystems